Mumbai, India (CNN) -- Corpses piled on top of Apurva Parikh as bullets killed two of his friends, lined up by terrorists against a wall at a hotel in India's financial hub.

Just minutes before the attackers had stormed The Oberoi, Parikh and his friends were having dinner. Moments later, they were standing with more than a dozen other guests, captives of a terror squad laying siege on several sites in Mumbai.

"Even today I'm not very comfortable when I meet the wives of the two friends I lost. I start thinking about myself that I am still guilty, I am still guilty. Why did I ask them to come?" he said a year after his friends, whom he had invited to dinner, were slain.

"So it's very easy to survive, to be a survivor, but in the end it's very difficult to live like that."

Parikh survived his gunshot wounds and was rescued by Indian security forces. But the 58-year-old businessman faced a long recovery, as did the nation of a billion plus following what has been billed India's "September 11," an incident that left 160 people dead last November.

The South Asian nation went into a quick review of its security apparatus. It also worked to build international pressure on Pakistan to bring the Mumbai suspects it alleged were Pakistanis to justice.

Corporate India also raised its guard, stepping up protection at businesses across the country, said Vikram Singh, chairman of the Central Association of Private Security Industry. "It's a 125 percent rise in demand (since the Mumbai attacks) for security systems alone. Before that it was 20 percent for them, which in itself was a good business," he said.

Driving into an Indian luxury hotel was easy before. Hand a key to a valet and walk into the lobby --- but not any more.

Video: Memories of Mumbai

Timeline: Indian terror attacks

Guards now tuck hand-held mirrors underneath vehicles to inspect hard-to-see areas, while visitors must pass through X-ray machines -- and their luggage through metal detectors -- before entering.

"It was an attack on India's economic leadership," Singh noted. Private security firms in India offer a manpower of about seven million, but demand for security is surging, Singh said. This in a country where the government says its police-population ratio is as low as 145 for 100,000 people.

Federal home minister P. Chidambaram --- appointed to the post after his predecessor quit following the Mumbai attacks -- acknowledged at a security conference two months ago that India had been tardy in building the capacity of its police forces.

"The measures that we have taken were long overdue and, in a sense, exposed the neglect and tardiness of the past. The center (federal government) and the states must share the blame for the remissness of the past," he said according to the text of his speech posted on the government 's Web site. Intelligence was key, he said.

In his speech, he urged police chiefs across the country to "reinvent" India's security system, but Chidambaram also made a tacit admission. "I still find that old mindsets and old habits persist. For example, state governments are unwilling --- or unable --- to revamp their recruitment procedures and make them quick, time bound and transparent," he said.

Some security experts say that certain key issues remain stuck in India's massive bureaucracy. The country was still debating jurisdiction of federal and state forces, said K.C. Singh, who had been coordinator for counter-terrorism in India's external affairs ministry.

"An all-India jurisdiction on terrorism is still not there," he said. Experts agree, however, that levels of international cooperation with India, especially in terms of intelligence-sharing, were higher than before.

The American ambassador to India, Timothy J. Roemer, told a news conference last week that the U.S. stood "shoulder-by-shoulder" and "hand-in-hand" with India in its counterterrorism efforts.

During talks Tuesday in Washington, U.S. President Barack Obama and Indian Prime Minister Manmohan Singh also decided to work closer on information-sharing to prevent the kind of militant attack that happened in Mumbai.

The attacks on India's largest city lasted four days and three nights.The attackers targeted numerous venues, taking over hotels and a Jewish center. Indian police have said 10 Pakistanis were involved in the deadly assault, nine of whom were killed in the carnage.

The lone surviving suspect has linked the coordinated shooting and bombing incidents to the leader of the Pakistan-based Lashkar-e-Tayyiba, a militant group banned in India. Many Mumbai residents don't feel any safer and are not convinced there won't be another attack despite the efforts to improve security.

Indian newspapers last Sunday carried stories about what had changed -- and what had not -- since last year. "The ebb from outrage to rage, its decline to umbrage and then a drift to amnesia is the narrative of the 12 months since the terrorist assault on Mumbai," wrote columnist M.J. Akbar in India's Sunday Times newspaper. "Even trauma has been reduced to television drama; once the scenes are played out, our bluster slowly splutters into silence."

But for survivors like Parikh, the events of those fateful days are still forefront in his mind. Parikh took lessons in the piano in the days that followed the attacks, seeking a refuge in soothing music.

But life has never returned to what it had been. "It's like a dead man living," he said. "I cease to feel anything now." He plans to revisit the spot where he was shot and his friends slain to try to find some closure.